Whether the campaign was on the rights of disabled people, army bullying of recruits, or the plight of victims of thalidomide, Jack Ashley proved that backbench MPs can achieve more than government ministers. But if he was no ordinary backbencher, having survived the shock of deafness, his secret weapon was no ordinary woman. Pauline Ashley, who has died of a heart attack aged 70, was the most effective political wife of her times and a powerful behind-the-scenes influence for social reforms which helped millions of people live better lives.

Born Pauline Crispin in Liverpool, the younger daughter of an insurance company manager, she was educated at Merchant Taylor's Girls school at Great Crosby, Northampton High school, and Sutton High school. She then won a mathematics scholarship to Girton College, Cambridge.

Pauline fell in love with Jack when she was just 19. He was an established political orator and working-class trade union activist who had, as a mature student at Gonville and Caius College, been sent on an American speaking tour. While reporting for the student paper she was sent to interview this tougher, controversial figure, who was most unlike the students of his day. They were married soon afterwards and began a lifelong partnership.

Their marriage lasted through numberless political campaigns, Jack's loss of hearing, many public positions, the birth and upbringing of three daughters, the arrival of nine grandchildren, general elections, party conferences and endless private laughter. Though she spent three years as a mathematics teacher in Sutton, most of Pauline's work was channelled through Jack's campaigning when he was first elected to the Commons in 1966.

After a bungled operation that left him deaf, the general assumption was that he would leave politics, but she was among those urging him not to quit. His reward for that courage - the successful campaigns that followed - was her reward too.

Had Jack not lost his hearing, he would almost certainly have become a government minister: Pauline would have become a minister's wife. Instead, she became something rather more useful in Labour politics - his adviser, researcher and joint tactician, immersing herself in briefings and planning lines of attack.

They worked together every day, on every campaign. Polite, with a ready grin, she could be underestimated by Jack's foes: she was in fact a woman of strong views and formidable skill - and at the same time she was bringing up three daughters. On the bleakest day, she would arrive in a whirlwind of good sense and optimism, often with a toolbox tucked under her arm.

She was also a busy public figure, even beyond Jack's campaigning. She took a master's degree in social administration at the London School of Economics in 1977, and worked on a York University and department of health and social services study into the spending and income patterns of families with handicapped children. Her book The Money Problems Of The Poor was published in 1983.

In 1985 she founded the Hearing Research Trust and was its chairman for 10 years. Among the public posts she held was a governorship of London's Royal National Throat, Nose and Ear Hospital, and chairman of the Electricity Consumers' Committee for the South East: in recent years her long interest in consumer rights - she was a great firer-off of letters - and her commitment to poorer families were meshing. Yet another career seemed to be beckoning.

Her interest was always public service, and the secret of her success was attention to detail. Jack Ashley provided the political language and the inborn fighting skill, but she would labour to help him find the killer facts. She was always looking for more.

Pauline's death was shocking because it was completely unexpected and, at 70, she had the appearance and energy of a woman decades younger. Brimming with life force, she never experienced a day of old age or a flash of self-pity. She did what politicians are supposed to - she changed others' lives for the better.

Her daughters went on to have successful careers themselves, heavily influenced by her quiet, sincere feminism and her own vigorous, can-do example. She enjoyed the company of nine grandchildren and became the linchpin of the extended Ashley family. Her husband and daughters, Jackie, Jane and Caroline, survive her.

· Pauline Ashley, the Lady Ashley of Stoke, campaigner, born August 2 1932; died July 28 2003.